Quartz Extreme
Some appealing graphics effects, such as the "rotating cube" effect you see when using Fast User Switching to switch users, are powered by Quartz Extreme. Quartz Extreme uses OpenGL and a supported graphics card to reduce the number of onscreen calculations being performed by the CPU. To take advantage of Quartz Extreme, you need one of the following graphics cards:
ATI: Any AGP-based ATI RADEON GPU with 16 MB VRAM or better.
NVIDIA: Any NVIDIA GeForce2 MX, GeForce3, GeForce4 MX, or GeForce4 Ti GPU with 16 MB VRAM or better.
Core Image
Other graphics effects and optimizations in Tiger, such as the ripple effect that shows when you place a widget on Dashboard, are driven by Core Image. When a programmable GPU is present, Core Image uses the graphics card for image processing operations, freeing the CPU for other tasks. To take advantage of Core Image, you need one of the following graphics cards:
ATI: ATI Mobility Radeon 9700, Radeon 9600 XT, 9800 XT, or X800 XT.
NVIDIA: GeForce FX Go 5200, GeForce FX 5200 Ultra, GeForce 6800 Ultra DDL, or GT DDL